Because of the rapid evolvement of information technology, digital electronic products have been widely applied to various life curricula of people. Speaking of portable digital storage device, the fast development of semiconductor fabrication process pushes the floppy diskette with larger size on the brink of elimination. Instead, the digital storage device with larger capacity and smaller size becomes the substitute of the floppy diskette, among which especially the storage device with the transmission interfaces of various memory cards, universal serial bus (USB) and external serial ATA (e-SATA) prevail as a result of the advantages of small size and large capacity.
Whereas, while the size of flash memory becomes smaller and smaller, it is easy to get lost upon being deposited and carried along by user.
Therefore, it is necessary to design an attached-type memory device to resolve the aforementioned issue.